Environmental effects for ship optimization assuming standard resistance prediction

Over the last decade, progressive restrictions on permitted emissions for maritime transport (Annex VI of MARPOL 73/78) have led to numerous optimizations for the sizing of Short Sea Shipping (SSS) vessels, their operation and propulsion systems. However, many of these optimization processes are based on resistance prediction methods with low accuracy levels as "early decision-making tools''. Consequently, their results have led to miscalculations of the propulsion power required to sail at optimal speeds. This study quantifies, in monetary terms, the environmental consequences of this lack of accuracy. To meet this aim, the paper assesses the performance deviations of a particular SSS feeder vessel, which was optimized by assuming standard resistance prediction techniques, when its propulsion power requirements for sailing at optimized speed were assessed through the Reynolds-Averaged Navier-Stokes method in Computational Fluid Dynamic simulations. The findings are analyzed in environmental terms to provide useful information about the consequences of underestimating the accuracy of the resistance prediction for SSS vessels.